Hey there!
To solve a system of equation by graphing, first make sure both your equations are solved for y so that you can graph it (make sure it is in a form like: y=mx+b or y=ax^2+bx+c, etc).
Then, graph the equations on the graph, and the point where all the lines intersect would be your answer which should look like: (x,y)
However, if you have linear equations and the lines are parallel to each other, then there is no solution. If the lines graph to be the same line, then your answer would be all real solutions.